diff --git a/doc/timezones.rdoc b/doc/timezones.rdoc
index 3e2122b43e9d37..18233b97aeb187 100644
--- a/doc/timezones.rdoc
+++ b/doc/timezones.rdoc
@@ -97,6 +97,6 @@ which will be called if defined:
 
 - +name+:
 
-  - Called when <tt>Marshal.dump(t) is invoked
+  - Called when <tt>Marshal.dump(t)</tt> is invoked
   - Argument: none.
   - Returns: the string name of the timezone.